Pneumatic-despatch-tube apparatus.



PATENTE-D MAR. 3,1908.

APPLIOATION FILED JULY 28. 1908.

Sane/who:

n. c. THE Mamas PETERS cu., WASHINGTON,

UNTTED STATES PATENT OFFICE.

CHARLES F. STODDARD, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO AMERICAN PNEUMATIC SERVICE COMPANY, OF DOVER, DELAWARE, A CORPORATION OF DELAWARE.

PNEUMATIC-DESPATCH-TUBE APPARATUS.

Specification of Letters Patent.

Patented March 3, 1908 Application filed July 28. 1906. Serial No. 328.197.

T 0 all whom it may concern:

Be it known that 1, CHARLES F. STODDARD, of Boston, in the county of Suffolk and State of Massachusetts, have invented certain new and useful Improvements in Pneumatic-Despatch-Tube Apparatus, of which the following is a specification.

My invention relates to the arrangement of pneumatic tube systems whereby the moisture of condensation is eliminated.

The figure shown in the drawing represents a system of two lines of pneumatic tubes, both radiating from the same station, the moisture being taken out of the air pumped into one of the lines by means of receivers which act as surface condensers, and out of the other one by means of using the return air from the first line which is dried.

A and A are compressors driven by the motors B and B respectively.

C and C are transmitters and D and D are receiving terminals.

E and E are reservoirs.

The blowers A and A, motors B and B, transmitters C and C, receiving terminals D and D and reservoirs E and E are all locat-ed at one station. Radiating from this station which is marked F are two lines of pneumatic tubes terminating at the stations G G. The air which propels the carriers in these two lines of pneumatic tubes is all com pressed at the central station F. The route of the air from the compressor A is through the pipe H and the reservoirs E and E are located in a cool place so that the moisture in the air will be precipitated and settle to the bottom of the tanks where it can be drawn off at any time. From the reservoirs E and E the air flows through the pipe H and the transmitter C and from thence to the pneumatic tube J and the receiving terminal D at the station G. From here it is conducted along the pipe H into the transmitter C and into the pneumatic tube J which returns to station F entering the receiving terminal D where it has reached practically atmospheric pressure. From the receiving terminal D the air passes through the pipe H back to the compressor A where it is again compressed and sent over the same route. On account of leaks in the pipes and pneumatic tubes, also on account of the lines at the re ceiving terminals D and D and the transmitters O and O also on account of the air taken away at the point H by the pipe H (the function of which will-be explained later) not as much air returns to the compressor through the pipe H as was delivered from the compressor A to the-pipe H, and this loss has to be made up at all times and the compressor A supplied with as much free air'as it delivers to the pipe H. In order the pipe H to the transmitter O ,*returning' to station F through the pneumatic tube J, entering the receiving terminal D at practically atmospheric pressure and returning to the compressor A through the pipes H and H As previously'explained as to the line running to station G, there is considerable loss of air due to leakages and also at the receiving terminals D and D and transmitters O and C so that the amount of air returning to the compressor A through pipe H is somewhat less than the amount delivered to the pipe H The deficiency in this case is made u from the pipe H The only source from w iich the pipe H can take air is the pipe H and as all the air in the pipe H has passed through the reservoirs E and E and through the pneumatic tubes J and J it has become thoroughly dried, therefore all the air supplied to the pneumatic tube line running from station F to station G has been thoroughly dried before it enters the compressor A and for this reason there will be no condensation of moisture in the pneumatic tubes J and J As before explained, all the' air which passes into the pneumatic tubes J and J 2 flows through the reservoirs E and E so that it is thoroughly dried. This arrangement makes it possible to supply dry air to any number of pneumatic tube lines with the use of but one reservoir outfit. Any number of pneumatic tube lines radiating from the central station F could draw their supply of air necessary to make up their deficiencies from the pipe H It sometimes happens when the ground is very cold and the temperature of the outside air relatively high, that the outside atmos phere is very humid, and the reservoir outfit in such cases is unable to precipitate all the moisture in the air. It is found Very desirable to concentrate this preci itation of moisture to one pneumatic tube inc and by the arrangement shown this is made possible, for after the air has passed through one pneumatic tube line, it always returns to atmospheric pressure thoroughly dried. It is understood here that the term dry air does not mean an absolute absence of moisture, but that the amount of moisture contained in the air is so small that when the air enters the pneumatic tube from the compressor, and is cooled by the great surface of contact and material offered by the walls of the tube, no precipitation of moisture will result therefrom.

Having thus described the nature of my invention and set forth a construction embodying the same what I claim as new and desire to secure by Letters Patent of the United States is:

1. In a pneumatic despatch tube apparatus, a series of pneumatic despatch tube lines, a series of blowers for said tube lines, an atmospheric connection to the blower of the first pneumatic tube line, and a connection between said first pneumatic tube line and the blower of the second pneumatic tube line for supplying air current to said pneumatic tube line and closed to the atmosphere.

2. In a pneumatic despatch tube apparatus, a series of pneumatic despatch tube lines, a series of blowers for said tube lines, an atmospheric connection to the blower of the first pneumatic tube line, means for drying the air in said first line, and a connection between said first pneumatic tube line and the blower of the second pneumatic tube line for supplying air current to said pneumatic tube line and closed to the atmosphere.

3. In a pneumatic despatch tube apparatus, a series of pneumatic despatch tube lines, a blower open on one side to the outside atmosphere and communicating at the other side with the transmitting terminal of the first tube line, a tank interposed in the communication between the blower and the first tube line, a pipe connecting the receiving terminal of the first tube line with the open side of the blower, a second blower communicating at one side with the transmitting terminal of the second tube line, and a closed communication leading to the other side of said second blower from the pipe connecting the receiving terminal of the first tube line with the first blower and said closed communication also leading from the receiving terminal of the second tube line.

In testimony whereof I have signed my name to this specification, in the presence of two subscribing witnesses, this twenty first day of July, A. D. 1906.

CHARLES F. STODDARD.

Witnesses:

W. E. BORNORD, A. S. TEMPLE. 

